In known commercial shelling processes, cracking tree nuts, e.g., hazelnuts, almonds, pecans, and the like, is accomplished by compressing the nut shells using a measured force. In these conventional processes, the nuts are passed between two hard surfaces (usually metal rollers) that are a fixed distance apart. This passage of the nuts compresses the nut shells until they crack.
However, the use of compression does not yield consistently good results. Damage to the nut kernels can run as high as 30% of the shelled product. This damage reduces considerably the value of the shelled kernel. Thus, it is important to minimize damage to nut kernels during the shelling process.
Most of this damage is caused by improper sizing of the nuts prior to passing them between the compression surfaces. That is, nuts that are too large are passed between rollers that are too close together. This not only cracks the shells, but also crushes the kernels. To add to the difficulty of properly sizing nuts, most tree nuts are not perfectly round. Instead, they are usually oblong shaped. Thus, the measured diameter of a nut obtained during the sizing process may be different than the diameter that is actually compressed during shelling. This can cause kernel damage, or alternatively, can result is a nut that passes through the cracker without getting shelled. Neither of these outcomes is desirable.
In addition to sizing, compression also requires that the nuts be cleaned and dried prior to shelling. This adds considerable cost to the overall shelling process. Indeed, drying a nutshell (which retains much of the moisture in a whole nut) and then discarding it to produce a shelled kernel represents a considerable waste of energy. It is important that these added costs of cleaning and drying are minimized or eliminated in a commercial shelling process.
In view of the foregoing problems and inefficiencies with conventional shelling processes, there is a need for an improved industrial nutcracker and shelling process for use in high-volume, commercial production environments.